Study Re-evaluates Evolution of Mammals

New York Times today summarizes recent research that shows that the ancestors of most mammals were alive long before the global extinction of dinosaurs and that it took a much longer time -- 10-15 million years -- than previously believed, for those lines to diversify and flourish. What does all that mean? It's too early to know, but certainly one thing: there's still much work to be done to fully understand the history of life on earth.